Automatic switch for use in telephone or like systems



Nov. 3, 1931. s. R. SMITH ET AL 1,830,138

AUTOMATIC SWITCH FOR USE IN TELEPHONE OR LIKE SYSTEMS Filed Aug. 12, 1929 Sidney REZjI'ZEZZ Efizl'h John Ellis D's Hinze Patented Nov. 3, 1931 UNITED STATES PATENT OFFICE- SIDNEY REYNELL SMITH, .OF LIVERPOOL, ENG-LAND, AND JOHN ELLIS OSTLINE, OF CHICAGO, ILLINOIS, ASSIGNORS T ASSOCIATED TELEPHONE AND TELEGRAPH COM- PANY, CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE AUTOMATIC SWITCH FOR USE IN TELEPHONE 0R LIKE SYSTEME Application filed August 12, 1929, Serial No. 385,164, and. in Great Britain August 23, 1928.

The present invention relates to automatic switches for use 7 intelephone or like systems and is particularly concerned with switches of the well-known type having motion in two directions, the motions preferably comprising first a vertical motion and then a rotary motion. It is often found desirable in switches of this type to arrange for certain circuit changes to be elfected for instance as soon as the switch leaves its normal position and also possibly as soon as it commences the second motion. Moreover, in the use of these switches it has become general practice for a switch which is adapted to hunt to find a free line to be advanced clear of its bank when no such line is available by taking what is generally an 11th rotary st p. When this occurs the wipers in general no longer engage bank contacts but circuit changes are brought about by the operation of so-called cam springs. A further requirement sometimes encountered is that itmay be desirable to operate springs on certain levels only, such springs generally being termed normal post springs. The design and mounting of springs of the above types involve a number of problems in order to ensure that the springs shall operate satisfactorily under all conditions and the chief object of the invention maybe said to be the provision of a contact springoperating assembly which shall be suitable for operating one or more of the abovefour types.

It has already been proposed to effect this object by making use ofla pivoted bar extending vertically for a length corresponding to the verticalv travel ofthe switch shaft which bar 'co-operates with a disc secured to the shaft and arranged to partake of both its vertical and rotary motions. \Vith this construction in order to obtain all the facilities above indicated it was necessary to employ specially contoured cam surfaces on both the pivoted bar and on the movable disc.

- According to the present invention however the member for operating the contact springs comprises a ball or roller of small vertical dimension for engaging with the operating member which accordingly com prises a two-dimensional surface on any suitable portion ofwhich projections may be located so as to operate the springs in different positionsof the switch shaft. Moreovor, as will be clear, these projections may be of dif-' ferent heights so as to permit a stepped operation of the contact springs.

The invention willbe better understood from the following description of a preferred form of carrying it into effect which is given by way of example only and should be taken into conjunction with the accompanying drawings comprising Figs.,l5. Of these drawings, Fig. 1 shows an enlarged view of a portion of the shaft of a switch of the well-known vertical and rotary type showing the location of and method of securing the special cam member, Fig. 2 is a sectional plan ofthe cam detached, while Figs. 3, 4 and show in plan the cam and the co-operating springs in three different positions the fiexure of the springs being somewhat exaggerated. The full details of the switch are not shown as these are well known and itwill'sufiice to state that the shaft which carries brushes or wipers is mounted vertically and is adapted to be raised bodily and then rotated during the operation of the switch.

Referring now to Fig. 1, the shaft is represented by 1 while 2 and 3 represent respectively the usual vertical and rotary teeth which are conveniently integral with the shaft. The cam member 4 is adapted to fit over the shaft and to be secured in position thereon by means of the set screws 5 and is conveniently located immediately beneath the rotary teeth. With the shape of the cam member 4 shown it is adapted to secure the operation ofrotary off-normal springs and also of eleventh-step cam springs, the spring assembly being so arranged that the springs are operated in two steps. It will be seen that the member t is cylindrical but is pro vided with a slot 9 into which the ball 10 is moved by the spring 11 when the switch is in normal position thereby closing the rotary off-normal springs 12 and 13. The ball 10 it will be seen is seated in a hole of slightly less diameter than that of the ball in the spring ll which is bent back to retain the ball in position. It is clear that since the slot 9 extends vertically for the whole length of the cam 4 the vertical movement of the shaft will produce no effect on the springs 12 and 13 and it will be seen also that the ball 10 will not introduce any appreciable frictional force 6 which'might prejudice the operation of the switch. s'soon as the switch shaft commences its rotary motion, however, the ball 10 rides on the c lindrical outer surface of cam 4 and springs 12 and 13am separated although the movement is not suificient to w close springs 14 and 15. These conditions are maintained in any rotary position in whichthe switch wipers are engaging their associated bank contacts but should the switch shaft be moved to the 11th step position the insert 6 which is secured to'the slot f by a pair of screws 8 engages the'b'all 10' and operates thesprings further so that-springs 14 and l b-are now closed'while springs 12 and 13 are further opened. The spring assembly to thefrai'ne -16'by-means of a suitable bracket, the s rings being insulated from oneanothor and rom the frame in the usual manner;

Since itis ner'ally desirable that the cam springsshou d beoperated in the 11th step position onoach levehthe insert 6 will be of snfieient 'len th to bring this about but it willreadily' e seen that the length ofthis member could quite well be alteredto give dilenent 'opera tin conditions. Similarly an amnion in the 'Zhapeof the slot Qfor instance the'provision of an additional depression at the-highestpoint might serve to secure the 1 operation of the vertical 'ofi-normal springs. Moreover any other desired operatihg cohditionsconld be obtained by-fixing to the-surliamofthe cam member suitable proiections which conld conveniently extend either vertically or-horizontally or could be of such size as to correspond to only one particular 'os'ition of the switch. 7 We c aim 1. In an antomatic'step-by step switch for tele hone systems, a switch shaft having a primar and a secondary movement, a cam member attached to said shaft, said cam member having a greater dimension in each moment of said switch shaft than the extent of a single step of the shaft, and a'set of contact springs on said switch operated in one manner by said cam member in 'the-initi al secondary movement of the shaft, and in another manner atthe end of the secondary movement. I

'2. In an automatic stepby-step switch for telephone switches, a switch shaft/having a primary and a 'secondar' movement, acam member attached to' anf moving with said shait, contact springs on said switch, an opcratin member control-led by said cam member for operating said contact springs in a plflralit of-difiereiit stages at difi'eront positions secondary 'inove'ment of said U switch slmft, said operating member' ha in'g member attached to a an engaging surface with said cam member of a dimension less than the extent of a single step in the primary motion of said switch.

3. In an automatic step-by-step switch for telephone systems, a switch shaft having a primary and a secondary movement, a cam member rigidly secured to said switch shaft, said cam member havin a dimension in each movement of said switc 1 shaft greater than asingle step of said shaft, contact springs controlled by said cam member, and inserts on said-cam member for operating said contact springs in the secondary movement of said switch shaft. a

4. In an automatic ste -by-step switchfor telephone systems, a switch shaft having a primary'and a secondarmovement, a cam member attached! an moving with said shaft, said cam member havin a greater dimension in each movement 0 the switch shaftthan the extent of a single step of the shaft, and a set of contact springs on said switch, said springs operated by said cam member in a plurality of stages at difienent positions ofthe secondary movement of said switch shaft.

In an automatiestep-by-step switch for telephone systems, a switch shaft having'a primary and-a secondar movement, a cam moving with said Q switch shaft, contact springs on said switch, an operating member controlled'by said cam member, said operating member comprising a ball loosely mounted on said contact springs, and means responsive to the second D0 ary movement of said switchshaft and said cam mcmberfor operating said ballto We! said contact springs.

6. In an automatic stepy-ste switchfor telephone systems havinga swit shafit with ins a vertical and a rotary motion, a cam member secured to said switch shaft,saidcam member having a length and a circmnfemnce greater than a sin step in either motion of said switch sha t, a setof contact springson said 'no switch,aba11 loose] mounted on one of said contact springs a in operative relation! said cam member, means on said oam member whensaid-switeh shaft isope'ra tedin itsvflrtical motion for maintaining said ball in Ms normal position, and means on-said cam member when'said switch shaft is operated in its rotary motion for oontroliling said ball to operate said contact springs. v 7.,In an automatic stepping switch for telephone systems, a switch shaft having '1. primary and a secondary-movement, a cum member secured to said switch shaft, said can member having a dimension ester than the extent-ofa single'step 0 f sa' ,switchm swo! contact springs on said switch, a ball on on one of said springs in operative relation to said 0am manner, means lll lid cam memberresponsive totheprimary movement of said switch shalt for I0 j l said ball roller in its normal position, and other means on said cam member responsive to the secondary movement of said switch shaft for operating said ball member to control said contact springs in a plurality of different stages.

In testimony whereof I, the said SIDNEY REYNELL SMITH, have signed my name at Liverpool, England, this 9th day of July,

SIDNEY REYNELL SMITH. In testimony whereof I, the said JOHN ELLIS OSTLINE, have signed my name this 8th day of Aug, 1929.

JOHN ELLIS OSTLINE. 

